Engineers that have a basic understanding of Docker can read the book sequentially, chapter by chapter. Tech leads who have an advanced understanding of Docker or have deployed applications in production before can go ahead and read Chapter 8, Onto Production, first to understand how Docker can fit in your existing applications. The following is a list of topics covered in this book:

Chapter 1, Preparing Docker Hosts, gives a quick refresher on setting up and running Docker. It documents the setup that you will be using throughout the book.

Chapter 2, Optimizing Docker Images, shows why it is important to tune your Docker images. A few tuning tips will be shown to improve the deployability and performance of our Docker containers.

Chapter 3, Automating Docker Deployments with Chef, shows how to automate the provisioning and setup of Docker hosts. It will discuss the importance of investing in automation and how it facilitates a scalable way of deploying your Docker containers.

Chapter 4, Monitoring Docker Hosts and Containers, gives a walk-through of setting up a monitoring system with Graphite and logging systems with an Elasticsearch-Logstash-Kibana (ELK) stack..

Chapter 5, Benchmarking, is a tutorial on how to use Apache JMeter to create workloads to benchmark the performance of your Docker containers. The chapter reviews the monitoring system you set up in Chapter 4, Monitoring Docker Hosts and Containers, to analyze some Docker application benchmark results, such as response time and throughput.

Chapter 6, Load Balancing, shows you how to configure and deploy an Nginx-based load balancer Docker container. The chapter also gives a tutorial on how to use the load balancer you set up to scale out the performance and deployability of our Docker applications.

Chapter 7, Troubleshooting Containers, illustrates how common debugging tools in a typical Linux system can be used to troubleshoot your Docker containers. They describe how each tool works and how it can read the diagnostics coming from your running Docker containers.

Chapter 8, Onto Production, synthesizes all the performance optimizations you did in the previous chapter and relates what it means to operate any web application in production with Docker.

A Linux workstation with a recent kernel is needed to serve as a host for Docker 1.10.0. This book uses Debian Jessie 8.2 as its base operating system to install and set up Docker.

More details on how to get Docker up and running is covered in Chapter 1, Preparing Docker Hosts.

This book is written for developers and operations people who want to deploy their Docker application and infrastructure to production. If you have learned the basics of Docker already but want to move forward to the next level, then this book is for you.

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "We will use --link <source>:<alias> to create a link from the source container, named source, to an alias called webapp."

A block of code is set as follows:

FROM ubuntu:14.04
MAINTAINER Docker Education Team <[email protected]>
RUN apt-get update
RUN DEBIAN_FRONTEND=noninteractive apt-get \
        install -y -q python-all python-pip 
ADD ./webapp/requirements.txt /tmp/requirements.txt
RUN pip install -qr /tmp/requirements.txt
ADD ./webapp /opt/webapp/
WORKDIR /opt/webapp
EXPOSE 5000
CMD ["python", "app.py"]

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

import os
from flask import Flask
app = Flask(__name__)
@app.route('/')
def hello():
    provider = str(os.environ.get('PROVIDER', 'world'))
    return 'Hello '+provider+'!'
if __name__ == '__main__':
    # Bind to PORT if defined, otherwise default to 5000.
    port = int(os.environ.get('PORT', 5000))
    app.run(host='0.0.0.0', port=port)

Any command-line input or output is written as follows:

dockerhost$ docker inspect -f "{{ .NetworkSettings.IPAddress }}" \
                           source
172.17.0.15
dockerhost$ docker inspect -f "{{ .NetworkSettings.IPAddress }}" \
                           destination
172.17.0.28
dockerhost$ iptables -L DOCKER
Chain DOCKER (1 references)
target     prot opt source         destination         
ACCEPT     tcp  --  172.17.0.28    172.17.0.15       tcp dpt:5000
ACCEPT     tcp  --  172.17.0.15    172.17.0.28       tcp spt:5000

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "Finally, click on Download Starter Kit."

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